(1304) Cephalometric Analysis on the Mentum-Hyoid-Palatal Angle in Obstructive Sleep Apnea

Introduction: Obstructive sleep apnea (OSA) significantly impacts individuals' quality of life, marked by recurrent airflow reduction or cessation during sleep. Diagnosis involves polysomnography (PSG), with head and neck cephalometry CT utilized to locate obstructions. Early identification of anatomical risk factors is crucial for guiding appropriate therapeutic interventions.

Methods: An observational study at Hospital Cuf Infante Santo/Tejo from November 2019 to January 2023 included patients from ENT appointments with snoring and sleep apnea. Those who underwent Drug Induced Sleep Endoscopy (DISE) and neck CT were selected; exclusions applied without these exams. Analyzed variables included gender, apnea-hypopnea index (AHI), DISE collapse degree (without, partial, or complete), and Mentum-Hyoid-Palate (MHP) angle.

Results: Analysis encompassed 70 men and 39 women, with men exhibiting higher OSA levels. Patient ages ranged from 18 to 68 (mean: 46.29 ± 10.216). MHP angle varied from 49.8º to 112.8º (mean: 74.91º ± 10.17). Statistically significant gender-based differences in the MHP angle were observed, with male patients exhibiting lower values. Spearman correlation revealed a weak, negative correlation between the MHP angle and AHI—smaller MHP angles associated with higher AHI. Similar correlations were found between the Mentohyoid-Palate angle and the base of the tongue and epiglottis, suggesting smaller angles correlate with higher collapse probability in these areas.

Conclusions: This study introduces a novel angle based on the hyoid bone, demonstrating a statistically significant relationship with OSA. However, limitations exist, as hyoid bone position can be influenced during respiratory and swallowing phases during cephalogram acquisition. Utilizing fixed structures for measurements may be pivotal in predicting individuals more prone to developing OSA.